I completely understand that master have two meanings: A man who has people working for him, especially servants or slaves; and An original recording, film, or document from which copies can be made.

I think it's just a bad English/mis-translation problem. I'm guessing @pmmmwh assumed 'master' meant like 主 in 奴隸主 (slave owner/master). Actually a better translation would be 師 like 功夫大師 (Kung Fu master). The specimen copies are made from.

The specimen copies are made from.